1. Field of the Invention
The present invention relates to a receiving technology, and it particularly relates to a receiving apparatus that receives a packet signal in which a known signal is placed in the beginning of the packet signal.
2. Description of the Related Art
Road-to-vehicle communication has been under investigation in an effort to prevent collision accidents of vehicles on a sudden encounter at an intersection. In a road-to-vehicle communication, information on conditions at an intersection is communicated between a roadside unit and an in-vehicle unit. Such a road-to-vehicle communication requires installation of roadside units, which means a great cost of time and money. In contrast to this, an inter-vehicular communication, in which information is communicated between in-vehicle units, has no need for installation of roadside units. In that case, current position information is detected in real time by GPS (Global Positioning System) or the like and the position information is exchanged between the in-vehicle units. Thus it is determined on which of the roads leading to the intersection the driver's vehicle and the other vehicles are located.
In an intelligent transport system (ITS), the packet signals are received from moving vehicles and therefore the received signals are likely to be subject to the effect of fading. An increased effect of fading deteriorates the accuracy of timing synchronization.